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Ilibrary of congres. 

| UNITED STATES OF AMERICA. J 



THE CONSERVATION OF 

■ 



GRAVITY AND HEAT: 



WITH 



SOME OF THE EFFECTS OF THESE FORCES 



OW THB 



PHYSICAL CONDITION OF THE EARTH; 



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A BRIEF APPLICATION 



TO THH 



SOLAR SYSTEM. 




-♦♦♦- 



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SPRINGFIELD: 
SAMUEL BOWLES AND COMPANY, PRINTERS. 

1864. 



■J J— 



Entered according to Act of Congress, in the year 1864, by 

HENRY W. CHAPIN, 

In the Clerk's office of the District Court of the District of Massachusetts. 



• • • 

• » 

• • • 



\ 




GRAVITY AND HEAT. 



In advancing a few thoughts on this subject, I ask the reader's 
indulgence, as I introduce the plainest practical illustrations. 

The general appearance of the earth leads to the belief, that, at 
6ome very early date in its history, it must have had a very high 
temperature, and, possibly, have been in a molten condition ; and 
many suppose that the central portion of the earth may now be in 
a fluid state. I shall endeavor to show that this must necessarily be 
the case, and, also, that the earth must, once, have been a mere mass 
of molten matter. At exactly what depth in the earth we should 
find the fluid line, (or the line where the fluid interior of the earth 
and the crust come in contact,) can be determined, or approximated, 
only by experiment. 

It is said that heat tends to equalize itself in matter. It tends to 
diffuse itself, and produce a uniform temperature m horizontal strata, 
and to equalize itself, in like matter of uniform density ; but it tends 
to concentrate in a perpendicular direction. The denser the same 
matter, the better are its conducting qualities. Heat has an affinity 
for, and is more readily conducted by, the denser strata, which, if 
undisturbed, usually underlie rarer strata ; thus concentrating the 
heat of the earth. Although heat is being conveyed from the more 
central portions of the earth to the surface, by the fluids and other 
agencies, and beyond the surface by the expansive force of the air, 
we find no increase of heat in the surface stratum, or in the exterior 
portion of the atmosphere. 

Effect of density, on conduction and capacity for heat. If we 
increase or reduce the amount of matter contained in a specified 
volume, we increase or reduce the amount of latent heat therein 
contained. This is apparent, by the unequal amount of heat evolved, 



when equal volumes of atmospheric air, of unequal densities, are 
compressed. The conducting power and capacity for heat, per 
cube, increase with the density. The capacity for latent heat in- 
creases with the density of the matter, and the capacity for sensible 
heat, with the density of the stratum in which it rests. If a paVti- 
cle of solid matter is depressed, or elevated in the atmosphere, to 
a denser, or rarer medium, the sensible heat increases, or decreases 
according to the variation in the density of the medium. This law 
is also made manifest, by boiling water, when under pressure, or in 
a vacuum, or lessening its capacity for heat, by causing it to expand 
bo as to form ice. The same increased capacity for heat may be 
seen in different substances, if they are fused while subjected to 
pressure. If we compress a piece of iron it becomes hot, and if the 
iron thus compressed was in a stratum, all the matter of which sus- 
tained an equal pressure, giving an equal density with the iron thus 
compressed, it would all be equally hot ; the permanency of the heat 
depending on the stability of the density of the stratum. 

Concentration of heat by compression and conduction. That we 
may realize the tendencies of heat to concentrate, and cause an in- 
crease of heat, as we descend in the earth, let us examine an arti- 
ficial stratum in a perpendicular column of sand. As there is a 
given amount of heat per grain, and as we find a perceptible increase 
in the number of grains, per inch, as we descend, we must acknowl- 
edge that there is a corresponding increase of heat. By casting a 
shaft of iron in a perpendicular position, the conditions being such, 
that all portions may be refrigerated, as nearly as possible at the 
same moment, we find that there is an increase in density and in 
heat, as we descend the shaft, as well as an increased conducting 
power in the same direction. If we continue to descend on this 
6haft, through the crust, we find the same continual increase in den- 
sity, conducting power, and in heat, as far as we can penetrate, and 
as these properties increase in matter, according to the pressure, we 
must calculate on the same increase in the impenetrable depths. 
Could we continue to descend, we should arrive at a temperature 
holding iron in a fluid state. 

Cause of unequal temperatures, in different localities at the same 
depth. In descending through the crust, which has been more or 
less disturbed, the increase in density and in heat would not be as 
regular, and would vary in different localities, at the same depth. 



The strata became hardened, while subjected to more or less pres- 
sure than they are, in the position they now occupy, and dissimilar 
rock and unlike strata vary, more or less, in their densities, conduct- 
ing powers, and capacities for heat, when formed under equal pres- 
sure. These disturbances and variations cause the thermometer to 
indicate different degrees of temperature, in different localities, at 
the same depth. 

The 'present appearance of the crust, and the figure of the earthy 
are not proofs of original fluidity. Whether the surface stratum 
was created fluid or solid ; whether the internal heat was uniformly, 
or partially distributed through the crust at creation, or was placed 
in the position it now occupies, are questions not determined by the 
present limits of the melted matter, the igneous appearance of the 
earth's crust, or its oblate spheroidal form. If the melted nucleus 
occupied its present limits at creation, it may since have imparted 
this igneous appearance ; as it is now passing and repassing through 
the crust ; (as I shall endeavor to show,) and the motion of the earth 
on its axis would produce the oblate form, whether the surface 
stratum was a solid or a fluid. But the conducting powers of the 
strata are such, that if the portion of the earth which is now the 
solid crust, was in a fluid state at creation, the heat would have 
receded to its present limits. 

The earth must have been in a fluid state at creation. As the 
density of the earth depends on the effect of gravitation, matter 
must have existed prior to its condensation by gravity, and heat 
have been uniformly distributed through the whole mass by the con- 
densation. The time must therefore have existed, when the earth 
was in a molten condition. Since the creation, gravitation has been 
producing its effects on the earth, and has by its powerful and all- 
pervading influence increased the density of matter, unequally, in 
different portions of the earth, by the pressure of particle on parti- 
cle, causing the central portion of the earth to be the more dense. 
Heat, having an affinity for the denser matter, has receded from the 
surface to the denser stratum. (The temperature of melted matter 
may be readily increased without causing it to expand, even if free 
from pressure.) The receding of heat from the surface to the denser 
stratum, caused a thickening of the fluid, and in process of time a 
solid, until we arrive at a depth at which matter ceases to contract 
by pressure, and heat ceases to recede. 



The expansive force of heat is overcome by pressure. With the 
increase of temperature, matter, at this depth, whether solid or fluid, 
yields to gravity, which has more force than the expansibility of 
heat, or the resistance of matter, causing perfect condensation at this 
point. That gravity produces this effect in a mass of matter, is evi- 
dent from the limited ability of solid matter to resist its force, to any 
great depth, as is made apparent by a perpendicular column of gran- 
ite or iron, a few miles in height, with an unlimited diameter ; the 
gravitating weight of which, is sufficient to crush its base. The 
sustaining strength of the shaft decreases if the temperature is in- 
creased, a slight pressure being sufficient to compress melted matter. 

The force of gravitation determines the density of matter.. As 
the density of matter, in all its forms, depends on the conditions 
produced by the force of gravitation, the expansive force of. heat 
depends on the incumbrance of gravity, and the expansive force of 
the matter heated. This is seen in many substances, when the com- 
paratively slight pressure of a portion of the atmosphere is removed 
from them, by placing them under an exhausted receiver. If we 
apply heat to water in this condition, we see how slight an in- 
cumbrance overcomes, in a measure, its expansive force, as, in this 
condition, it expands to steam with less heat. Again if we fill a hol- 
low tube, a few feet in length, with molten matter, when in a hori- 
zontal position, and then increase the pressure on the particle by 
placing it in a perpendicular position, its contents are increased in 
density, and the same matter fails to fill the tube, in its new position. 
If the matter contained in the tube w r as not heated, its density would 
not be affected by the change of position and slight increase of pres- 
sure. These experiments show that the density of matter and the 
expansive force of heat, (when taken in connection with the expan- 
sive force of the matter heated,) depend on gravitation and the 
weight of particle on particle ; and that the expansive force of heat, 
in matter, is more readily overcome, when the matter is heated. As 
the same matter contains the same heat in its new position and de- 
creased figure, it contains more heat per cube. The increase in 
density and capacity for heat is greater, in the lower extremity of 
the tube. 

Perject condensation of the fluid stratum. The force of gravity, 
on the crust of the earth, causes a regular increase in density, as we 
descend, until we arrive at a point where matter ceases to contract 



by pressure, or by refrigeration. This is proved, by the facts that 
matter cannot be annihilated by pressure, and that the contraction of 
matter by refrigeration decreases as the pressure is increased, its 
expansive force having yielded to the pressure, before congelation 
took place. This point must also be comparatively near the surface 
of the earth, as the length of the perpendicular column indicates. 
And, as has been shown, matter is increasing in density according to 
the pressure, as far as we can penetrate ; but this increase is not 
maintained to any very great depth, as if so, the earth would be 
vastly heavier than it now is. From this line inwards, the atoms 
come in contact, forming a perfectly condensed and uniform stratum. 
As this stratum is of uniform density, the fluid heat ceases to recede. 
Matter outside of this line is lighter, (per cube,) and retains less 
heat. Matter inside of this line is of uniform density and heat. 

Comparative density of different strata. The fluid stratum must 
be more dense than the solid crust, for a solid cannot rest on a fluid 
less dense than itself. It would sink, as would ice, on a lake that 
should be overloaded, and if the crust was as dense as the fluid 
stratum, it would itself be made a fluid by the condensation, and its 
temperature would be increased in intensity to that of the fluid 
stratum, as its powers of conduction increase with its density. The 
solid crust rests on the fluid stratum at that point in the earth, where 
the solid and the fluid are of equal density and heat. The crust 
floats on the melted nucleus, and decreases in density and in heat as 
we proceed up, and heat is not conducted from the fluid stratum to 
the surface, as matter decreases in density and in conducting power 
in that direction. The crust having been disturbed, the decrease in 
density is not regular ; but the power of conduction maintains a very 
regular decrease, owing to the intersection of veins, dikes, fissures 
and the like, at the time of the various disturbances. 

Original formation of the crust, and of surface inequalities. The 
fluid heat that, at creation, was distributed through that portion of 
matter, which is now the solid crust, has receded to the denser 
stratum. The refrigeration and contraction of the surface stratum 
took place first, that being the least dense, and the inferior strata of 
the crust, being refrigerated subsequently, caused a lateral pressure 
on the surface stratum, equal to the contraction of matter in the infe- 
rior strata by refrigeration, or the extra surface found in the heights 
and depressions, on the surface of the earth. 



8 

Reduction of diameter by refrigeration. If we allow the crust to 
be thirty, or even fifty miles in thickness, and to have contracted in 
congealing, as much as iron would, in the same circumstances, or as 
granite is said to contract, which would be one-eighth of an inch per 
foot, on the surface of the earth, and none at the other extremity, — 
viz., the fluid line, (the expansive force of heat, at that depth, having 
been overcome by pressure,) — the medium contraction of the crust 
might then have been less than one-sixteenth of an inch per foot, as 
some substances are known to contract less than one-eighth of an 
inch per foot, in congealing. Thus the earth would have been but a 
very few thousand feet larger in diameter, when in its fluid state, 
than it now is. A crust thirty miles in depth, may seem thin and 
unstable, while ice a foot in thickness will sustain many tons, and, a 
few rods in thickness, would sustain our largest structures. 

Refrigeration and contraction caused great disturbance. As the 
refrigeration of the inferior strata advanced, a mechanical advantage 
was gained by the heavier portions of the solid crust, over the lighter. 
This, together with the lateral pressure on the surface stratum, ele- 
vated the mountains and depressed the valleys. As the force of 
gravity on elevated matter decreases inversely as the square of its 
distance from the center of the earth, the continents and mountains 
as they were uplifted, became self-sustaining. As their weight de- 
creased by their elevation, the sustaining spherical form of the crust 
increased by that elevation, adding part of the weight of the mount- 
ains and continents to the more depressed portions, bringing an un- 
even pressure on many portions of the crust, causing currents and 
counter-currents and great changes in the solid strata, by the equal- 
izing process which nature maintains. 

The leveling forces are not reducing the surface of the earth to a 
plain. The changes which are now taking place are comparatively 
trifling, more local, and are produced mostly by the aqueous agents, 
which are changing the position of matter, and disturbing the equi- 
librium which exists in the crust. But the tendencies of nature to 
level the surface of the earth, by means of the aqueous agents and 
other forces, are counterbalanced. The removal of matter from one 
locality on the surface of the earth, allows as much matter to expand 
at the fluid line, as is caused to contract in another portion, by the 
addition of matter. The melted nucleus conforms to the center of 
pressure, as it is a perfect self-adjuster. Any portion of the crust, 



becoming overloaded, is crushed by the force of gravity on the super- 
incumbent mass, and made a fluid by the condensation ; while an 
equal amount of the melted matter rises, with those portions which 
are being made lighter, above the line of uniform density. There 
being less pressure it expands, has less capacity for heat, and in pro- 
cess of time, the fluid heat recedes from it as at creation ; restoring 
a uniform pressure, density, and temperature, to every portion of the 
crust, coming in contact with the fluid stratum. 

The crust of unequal thickness. Perpetual restoration of mount- 
ains. The crust varies in thickness, in different localities, producing 
this uniformity of pressure. The unequal centrifugal force, in differ- 
ent portions of the earth, does not affect the pressure, or the thickness 
of the crust, only as it affects gravity. The thickness of the crust 
increases as we approach the equator, as the force of gravity de- 
creases, on account of the spheroidal figure of the earth. The crust 
at the sea-level indicates a medium thickness, and the more elevated 
portions show an increase in thickness, equal to the elevation. 

If matter is removed from any locality on the surface of the earth, 
the melted nucleus recedes from that locality. If matter is added 
to any district, the melted nucleus approaches that district. The ap- 
proach of the fluid stratum to any point, is equal to the subsidence 
of that point ; and its recession from any point is equal to the up- 
heaval of that point, when compared with the level of the sea ; for 
while the melted nucleus conforms to the center of pressure, the sea 
maintains a level to that center. 

Portions of the crust the most liable to fracture. Formation of 
volcanoes. When large deposits of matter are being made in any 
locality, that locality is subsiding ; while the district from which the 
matter is being removed is rising, bringing a longitudinal strain on 
the latter, and a lateral pressure on the former. The resistance of 
rock strata to a crushing force, far exceeds its tension strength. 
Those portions of the crust which receive a longitudinal strain, are 
liable to fracture ; as some point near, or at the summit of those 
which are being uplifted ; while those portions which are receiving 
the greatest longitudinal strain, and are the most liable to fracture, 
and allow the melted nucleus to be forced up to the surface, and at 
times to produce volcanoes, are those lying nearly equidistant be- 
tween the points of greatest upheaval and depression, and are near 
the level of the sea. Some portion of the crust near that line and 
2 



10 

below it, is receiving matter and is subsiding; and some portion near 
that line and above it, is losing matter and is being uplifted, indica- 
ting the line upon which faults are formed. 

Continual transposition of oceans and continents; the melted nu- 
cleus, and the crust. When large deposits of foreign matter are 
being made near the coast, that portion of the continent is subsiding. 
If the district from which matter is removed, lies contiguous to any- 
sea or ocean, that sea or ocean is retiring. Thus the sea is encroach- 
ing on the land, and the land on the sea, as alternately the solid crust 
is forming the bed of an ocean, the summit of a mountain, or is be- 
ing condensed and made a fluid : and on the other hand the melted 
nucleus is expanding and being refrigerated, forming the inferior 
stratum of plutonic rock. This rock is being formed, at points under- 
lying the localities where the crust is being lightened, and is laid bare 
by the leveling forces on the summit of some lofty mountain, and in 
its turn, furnishes material for aqueous strata. 

Older mountains not the higher. Affect of changes of level on 
climate. As these older mountains, in time, gradually subside, the 
plutonic rock is found in different localities at all the intermediate 
levels between these elevated positions and the ocean. The strati- 
fied rocks are found at all the intermediate levels between the ocean, 
and the summit of the lofty, and more recently formed mountains- 
From the position of the organic remains found in these stratified 
rocks, it is evident that they have at times formed the bed of the 
ocean. The uplifting of the crust from the level of the ocean to the 
line of perpetual frost, with the consequent changes in the currents 
of the ocean, gives to the same locality an ever-varying climate. 

Localities where changes of level are the most frequent and per- 
ceptible. Since the earth as a whole, has ceased to contract, these 
changes have become less rapid; but a few centuries makes them 
visible, in many localities on the surface of the earth. The subsi- 
dence may be seen at, or near, the points where large quantities of 
foreign matter are being deposited, as at the estuaries of some rivers, 
where trees are found buried in a growing posture below the level 
of the sea ; as well as at other points where edifices have been im- 
mersed. Promontories and even mountains are being submerged, 
and are forming islands, in those portions of a continent which are 
subsiding, and other mountains composed of various strata, are being 
formed on those portions which are losing matter and are being up- 



11 

lifted. The uplifting of the land is the most apparent, at points 
where extended high lands or mountain ranges approach, or lie con- 
tiguous to the sea, as may be seen on the western coast of South 
America. In favorable circumstances, these changes of level are 
the most rapid, where the surface inequalities are the most visible, 
as is seen in the warmer climates. 

Visible effects of upheaval and depression. Location of volcanoes 
defined. The effects of this upheaval and depression are indelibly 
stamped, in various ways, on the solid crust ; as is seen in the various 
fractures of cleavage, dislocation and the like. Fractures which were 
produced in the surface stratum, near, or at the summit of an uplift, 
are usually represented by a rent : those underlying the same locality 
in the inferior, hotter, and more plastic strata, by a fold. Before 
the faults were disturbed, they represented a line near the level of 
the ocean. But if erosion and denudation were very unequal on 
opposite sides of the continent, they may represent a somewhat 
higher altitude. As volcanoes are formed on those lines where the 
changes of level are the most frequent, and where the crust receives 
the greatest longitudinal strain, they are found more or less in belts 
or bands. 

Localities exposed to frequent fluctuations. It is not my purpose 
to describe the geographical or geological features of the earth ; to 
note the increase of heat as we descend through the crust, or to 
point out the localities where changes have been the most frequent, 
or disturbances the most violent. These have been done by many 
observers, with more or less care and minuteness. I propose to con- 
fine myself to the origin and cause of these conditions and disturb- 
ances, and indicate the portion of the , crust, the conditions of the 
elements, and the season of the year in which they are more likely 
to occur. As the currents of seas and oceans are subjected to more 
frequent fluctuations than inland streams are, islands, peninsulas, and 
the like are subjected to more frequent fluctuations in their upheaval 
and depression, than is the case with the main land ; as the peninsula 
of Italy very plainly indicates. It has been suggested by writers on 
physical geography, that those inland tropical seas, which are receiv- 
ing a constant influx of salt water through their straits, might be 
filling up with salt, from the almost constant evaporation from their 
surfaces. As previously shown, any extended portions of land, sea, 
or ocean, which are receiving large deposits of foreign matter, whether 



12 

of Salt, coral, or any other substance, are subsiding. There may be 
exceptions to this, however. A point may be uplifted, when receiv- 
ing slight deposits of foreign matter, if it is located nearly equidistant 
between two points, each of which are receiving an excess of matter, 
and are subsiding. The uplift would be produced, by the solidity of 
the crust, before it is sufficiently overloaded to cause subsidence, as 
some coral islands in the central portion of the Pacific ocean may 
possibly indicate. Some localities are being uplifted when receiving 
deposits, if the district, as a whole, is losing an excess of matter, as 
is seen in some valleys, lake and volcanic regions. Lakes thus 
situated are gradually filling up, as is the case with Lake Geneva. 
Other localities are being depressed while being lightened, if the 
surrounding district is receiving an excess of matter, as some islands, 
peninsulas, capes, promontories, and similar localities may indi- 
cate. 

Familiar examples. That the heavier portions of the crust should 
be subsiding and the lighter rising, is in accordance with the effect 
produced on an arch, the equilibrium of which is disturbed by light- 
ening or overloading any portion of its span. The heavier portion 
subsides, causing the lighter to rise. 

It is evident, that the uplifted portions of the crust would be sus- 
tained in their elevated positions, as they lose a portion of their 
weight in being elevated, and as a part of their weight is added to 
the more depressed portions of the crust, in consequence of that 
elevation. That portions of the crust are being uplifted, and that a 
part of their weight rests on the valleys and more depressed por- 
tions, is manifest from the frequent landslides. If it were not so, 
landslides would be unknown ; and if a part of the weight of the 
more elevated portions did not rest on the more depressed, perpen- 
dicular gravel and earth banks would be a familiar feature in our 
landscape. 

The uplifts are bounded by depressions. Their vicissitudes are 
equal. As the crust floats on the melted nucleus, and the inequalities 
on the surface poise each other, great mountain chains must be bal- 
anced by a deep sea, or a vast extent of low, level plain. Astronomy 
teaches that the diameter of the earth is invariable : the upheavals 
and depressions must, therefore, be equal. These motions counter- 
balance the effect of the leveling forces, and maintain an equilibrium 
in the inequalities on the surface of the earth. 



13 

General derangement of landmarks. The leveling forces are not 
producing any very perceptible effect on the rocks which project 
above the line of perpetual frost, as is evident from their jagged ap- 
pearance, but at a slightly inferior level they are working with great 
energy ; as is seen in the heaving of the surface, owing to the alter- 
nate freezing and thawing, and in the action of glaciers and torrents ; 
removing large quantities of matter, undermining precipices, forming 
overhanging cliffs, and at times frightful avalanches of rock and 
earth. As the particles of rock and earth are removed, they seek 
an inferior level and are increased in weight, and by being trans- 
ported to a greater or less distance, they are deranging, in a greater 
or less degree, the geographical landmarks. 

The cause of earthquakes. Although the crust has an arching 
and self-sustaining form, its sustaining strength is limited, by the 
same limited ability existing in the arch and in the perpendicular 
column. As the diameter of the column was unlimited, it may rep- 
resent the crust of the earth. The solidity and sustaining strength 
of the crust are such, that it resists this gradually leveling process of 
overloading and lightening for a while, before yielding to a new 
position. This resistance causes the changes of level and the trans- 
ition in the density of matter, to be more or less paroxysmal, rending 
the solid crust, producing shocks or earthquakes by the fracture and 
concussion, at times forming new, or reanimating old volcanoes, 
causing great energy and activity at the vents. 

The motions and fractures are unlike at different altitudes. The 
disturbance produced by the fracturing of the crust varies with the 
nature of the soil, the face of the country, and the height above the 
level of the sea, at which the fractures occur. The motions imparted 
to the crust on the line upon which faults are formed, are very com- 
plicated and violent, as a portion of the crust on this line is being 
uplifted, and a portion depressed. When the crust yields to the 
£ accumulating forces and becomes fractured, it frequently opens and 
closes again. These fractures and complicated motions disturb the 
% solid crust, in various ways that we from time to time experience. 
The unobstructed motion of matter at the vents may, in a measure, 
counteract the disturbing effect of the concussion on the surrounding 
crust. Slight secondary forces are sometimes introduced by the ad- 
mission of fluids into the fractures of the crust, forming steam, gasses, 
and the like. 



14 

The conditions, localities, times and seasons most conducive of 
earthquakes. Earthquakes, or the fracturing of the crust, more fre- 
quently take place, when the disturbing forces are the most intense 
and act the most in unison ; as when the earth is in that part of its 
orbit nearest the sun and moon, or when the sun and moon act in 
conjunction, with a high tide resting on the portion about to be de- 
pressed ; *or when there is a sudden decrease in the pressure of the 
atmosphere on the continent, or on a portion of the continent and 
ocean. While the pressure would be greatly reduced on the land, 
(the portion which is being elevated,) the waters of the surrounding 
ocean would flow in, on account of the greater pressure elsewhere, 
and keep up the weight on those portions being depressed ; viz : — 
those portions of the crust lying below the ocean. There are also 
atmospheric tides which correspond with the tides of the ocean. 
When these tides are at their maximum, at a given point on the 
ocean, (other things being favorable,) the ebb in the atmospheric tide 
causes the barometer to be at its minimum, on the adjoining conti- 
nent. As the sun passes the equator twice yearly, and the spring 
tides are the highest when the sun is in that vicinity, earthquakes are 
most frequent when the sun is near the equinox. 

As the land on the surface of the earth is more largely situated 
in the northern hemisphere, and has the least amount of ice, snow, 
and moisture resting upon it, when the sun has its most northern 
declination ; and as the disturbing effect of the leveling forces have 
been accumulating during the year, and the vertex of the tidal-wave 
in a measure follows the course of the sun, in its journey north and 
south, earthquakes frequently occur when the sun returns to the 
summer solstice. 

Effect of centripetal and centrifugal forces on density. Irrespect- 
ive of the conditions which control the expansive force of heat, a 
permanent increase or decrease in gravity would cause a permanent 
increase or decrease in the density of matter. When the distance is \ 
diminished between the sun and any of the planets, the centripetal 
and centrifugal forces are increased. As these forces act in direct 
opposition to each other on matter, the tendency is to increase, or 
reduce the density of the bodies, according as these forces are in- 
creased or reduced. This may be demonstrated by matter under 
our immediate control. The extreme eccentricity of the orbits of 
comets and their tenuity of substance, causes some of their disks to 



15 

be sensibly reduced as they approach the sun. As the distance be- 
tween the sun, moon, and earth is continually varying, and as the 
matter of the earth is alternately approaching, and receding from, 
the moon, by its motion on its axis, the density of the earth is very 
slightly affected by these varying influences. The slight effects of 
these disturbing forces are made visible, by their accumulation at the 
vents, and cause continual motion in the melted matter there. 

Volcanoes will always exist on the earth. The reason of their over- 
flowing at different altitudes, and more frequently near the level of the 
sea. As the artisan may not be able to braze up the last aperture in 
the thin shell of a hollow metallic globe a few inches in diameter, on 
account of the continually varying pressure of the air resting on the 
inner and outer surfaces, so nature fails to refrigerate the melted 
matter in the vents, and close up the last apertures in the crust, on 
account of the constant transposition of the matter in the vents, 
caused by the ever-varying pressure against its inner and outer sur- 
faces. If the fluid stratum could be in a state of perfect rest, the 
uniform pressure of the solid crust resting upon its surface, would 
force it up through every vent and fissure, to a height nearly equal 
to that of the the fluid stratum before any refrigeration and contrac- 
tion took place. On account of its continual motion it may be car- 
ried still further upward by inertia, and forms cones above that point. 
As the melted nucleus conforms to the center of pressure, and the 
sea maintains a level to that center, the height to which the fluid 
would rise above the surface of the earth, should be calculated from 
the level of the sea, volcanoes being more likely to overflow at the 
sea-level, and less likely on the higher points, where the crust is 
thicker. The crust varies in thickness in different localities, owing 
to the variation in density, in the force of gravity, and the unequal 
sustaining strength of the spherical form of the crust in different dis- 
tricts and elevations. These inequalities and paroxysmal transitions 
in the density of matter, and the unequal egress of the fluid at the 
vents, giving different degrees of momentum, cause the melted mat- 
ter to overflow or stand in the vents at different heights, as regards 
the level of the sea. 

Origin of unlike igneous rock. As unlike matter in dissimilar 
inferior strata is being condensed and made a fluid, at different times, 
by the transposition of matter on the surface, various substances may 
be ejected from the same volcanoes or fissures, at different times. 



16 

While granite may be the basis of condensed matter, the various trap 
rocks may be the product of different fused strata. 

To determine the weight of the earth, we should calculate the 
medium density of the crust, and the density of the fluid stratum. 

There must he a melted nucleus. Frozen localities may remain 
congealed. That the crust is thin, and the interior of the earth a 
fluid, is evident from the limited ability of refrigerated matter but a 
few miles below the surface, to resist the superincumbent mass of the 
crust, as is indicated in the base of the perpendicular column. If 
we take the intensity of the stratum of equitable temperature in con- 
nection with the centralizing tendency of the crust, it shows that the 
interior stratum must be intensely hot. Although heat tends to dif- 
fuse a uniform temperature in horizontal strata; when the density 
becomes sufficiently reduced to admitof freezing, the power of con- 
duction has become nearly or quite obliterated, so that it may remain 
for ages congealed, before being thawed by conduction, as many per- 
manently frozen wells and various localities indicate. 

The internal heat is sufficiently intense to fuse the crust. That we 
may better realize the transitions through which the heat and matter 
of the earth are capable of passing, let us take fifty parts of matter 
and subject forty-nine parts, more or less, in a crucible, to an intense 
fluid heat, and then add the remainder. It would all become a fluid. 
If the crust encircling the fluid stratum should be broken up and 
pushed into the melted mass, it would be melted, (as heat tends to 
diffuse a uniform temperature in horizontal strata,) and the earth 
would return to its fluid state. In process of time the heat would 
return to its present limits, and the earth would assume its present 
condition. If, after being thus melted, the heat could not recede to 
its present position, it could not now maintain its present limits. If 
it was thus melted, the matter composing the crust would be ex- 
panded, the inequalities of the surface would be leveled, and the 
sphere enlarged, but the surface of the earth would not be very 
materially increased, when we consider the undulations and surface 
wrinkles of the present formation. 

Conservation of Gravity and Heat. In establishing the 
law of the conservation of gravity and heat, it becomes necessary to 
show that heat disappears from, or increases by the cube in two 
bodies, as they approach or recede from each other, in the same 



17 

ratio as tha force of gravity increases, or decreases in those bodies. 
Gravity is a constant force, and heat its equivalent when resisted. 
When two bodies are attracted towards each other, the equivalent of 
the force of gravity is found in their accelerated motion. When 
that motion is resisted by any force, matter is condensed and heat 
made visible. 

If we should remove a particle of matter from any point on the 
surface of the earth, a portion of the fluid stratum underlying that 
point would expand, and retain less heat per cube. The solidity of 
the crust might resist a sudden transition, but the final result would 
not be effected by the delay. The melted nucleus would be dimin- 
ished by the removal. If the matter thus removed was elevated to 
the upper atmosphere, (as might be represented by attaching a body 
to a balloon,) the loss of heat in a portion of the fluid stratum under- 
lying the point from which the matter was removed, would be the 
same, and heat would have vanished from that point by the cube, as 
gravity would, by the square of the distance ; and the elevated body 
would rest in a medium of air, less dense than that from which it 
was removed. As the tendency of heat, in every stratum or me- 
dium, is to diffuse a uniform temperature in a horizontal direction, the 
temperature of the elevated body would be reduced in intensity, to 
that of the medium in which it rests, and the frosts of a perpetual 
winter might rest upon it. But if the body elevated has a fixed 
form, that has not allowed it to expand in an equal ratio with the 
loss of gravity, heat has not been vanishing by the cube, as has 
gravity by the square of the distance. This can be made very 
apparent, if we imagine the body elevated a second time, and this 
time beyond the influence of the earth. In this last removal, while 
gravity has been vanishing inversely as the square of the distance, 
heat has not been vanishing by the cube, as there has been no con- 
veying currents or conducting mediums, and chiefly as the body has 
not been expanding. We therefore find that in elevating the body 
and thereby causing gravity to vanish, we have not removed the 
force of cohesion from the particles. 

As matter must have been created prior to the condensing effect 
of gravity on the same, giving it form, gravity must have condensed 
matter before cohesion took effect in the particles. As gravity pro- 
duced its effects first, it must vanish first. As cohesion originally 
fixed its firm grasp on the particles of solid matter by refrigeration, 
3 



18 

when the matter was under the condensing effect of gravity, heat 
must be restored to the solid matter, to cause cohesion to vanish, 
after the condensing effect of gravity shall have been removed. As 
gravity has vanished from the elevated body, if we should restore 
the previously refrigerated heat and fuse the elevated body, cohesion 
and heat would vanish as has gravity, and matter would disappear by 
the cube, in an equal ratio. The more rare the same substance, the 
greater is its capacity for latent heat per pound. 

As matter existed prior to its condensation by gravity, it might exist 
if gravitation should be removed. Gravity has been constantly pro- 
ducing its effects on the earth since the creative act, and that we 
may better understand its original, as well as its present effects, and 
as we are led to believe by Holy "Writ* that the force of gravitation 
may have been suspended or removed from a limited amount of mat- 
ter, let us for a moment consider the effect, if the force of gravitation 
should be miraculously removed from the matter composing the earth. 
If it should be gradually removed, heat would be uniformly diffused 
through the whole mass,| and matter would expand. The prophecy 
in regard to the final consummation of all things would be literally 
fulfilled. The heat refrigerated from the solid crust, when under 
the condensing effect of gravity, would be restored. The elements 
would " melt with fervent heat and be dissolved," and the expansion 
of matter would cause the earth to "pass away with a great noise." 
Gravity, cohesion, and heat would vanish, and matter would disap- 
pear by the cube, in an equal ratio. While gravitation has the 
power to condense the rarest nebular matter and produce heat, on 
the other hand, heat has the power to expand the same matter to its 
original condition, if ever gravitation should be removed. 

Formation of a planet from nebulous matter. As the projectile 
forces have not been suspended, if we should restore gravitation to 
the particles of matter from which it has been removed, nature, with 
her present laws, would restore the present density, figure, and physi- 
cal condition of the earth, but not its geographical positions. Matter 
would be condensed and heat evolved. That portion of matter lying 

- 

* Exodus xiv. 22 ; II. Kings vi. G; Matthew xiv. 2G-29, and similar passages. 

f If it was removed rapidly, fragments of solid matter corresponding to me- 
teoric matter, might bo hurled into the surrounding space. 



19 

nearest the surface, not being perfectly condensed by gravity, would 
be refrigerated and form the crust. 

Ages must have elapsed since the force of gravitation was imparted 
to the matter composing the earth. As a year is not sufficiently long, 
to refrigerate the ruins of some stately mansion that has been de- 
stroyed by fire, and years often elapse in the refrigeration of matter, 
a few feet in thickness, ejected from a volcano at a single eruption ; 
what ages must have elapsed in the refrigeration of the solid crust 
of the earth : epochs during which the temperature has been grad- 
ually decreasing on the surface. As all portions have retained heat 
equal to their density and capacity, and to the density of the stratum 
in which they are found, the interior stratum being perfectly con- 
densed is intensely hot, and in the economy of nature it must be so, 
in order to maintain motion in the fluids and vitalize all nature. On 
account of the centralizing tendency of the crust, if the interior 
stratum was not intensely hot, the surface stratum would be intensely 
cold. 

The constant transposition of the fluids tends to equalization of 
heat ; as is shown by the direction and temperature of the prevailing 
currents. The denudating and transporting forces of the currents of 
the ocean, give the continents their form. The currents in the atmos- 
phere tend to equalize its temperature, and its conducting power and 
capacity for latent heat increase, by the cube, with its density, thereby 
increasing the refrigerating forces. Hence a dense atmosphere as 
indicated by the barometer, on a still clear evening, facilitates the 
deposit of dew, or the appearance of frost. 

In consequence of the centrifugal force and spheroidal figure of 
the earth, the tendency originally must have been, to form the ine- 
qualities on the surface of the earth, nearly parallel with the equator. 
But the unequal temperature and equalizing tendencies of the air 
and water, in different portions of the earth, cause constant transpo- 
sition of the fluids at the poles and equator, maintaining sea-commu- 
nication in a transverse direction, from the vicinity of pole to pole, 
giving form and outline to the continents, and determining in the 
main the direction of mountain chains. Currents moving in a 
northerly and southerly direction, (as the Gulf stream,) move more 
or less in curves, owing to the rotation of the earth on its axis ; and 
always tend to flow in a line determined by a composition of these 
forces, wearing a'way all intervening barriers in the course of time. 



20 

On account of the centralizing tendency of the crust, if the inter- 
nal fires should become extinct, the pulsations of the globe would 
cease. The sun would continue to give motion to the atmosphere, 
but the earth might be transformed into a sterile waste. 

The unequal temperature and density of water in the earth, a cause 
of springs. If we apply heat to the lower extremity of a column of 
water, the equalizing tendency is again made visible by two currents, 
the warm current ascending, conveying the heat in an opposite direc- 
tion from that in which it is conveyed by conduction, and the cold, 
descending, showing that the internal heat produces motion and 
causes springs, and that artesian wells would overflow at, or above, 
the surface of the earth, if it was a perfect sphere, as water stands 
the highest in the ascending limb. The variation in height of the 
water in two contiguous columns, depends on the length, and on the 
unequal temperature, or weight, per cube, of the water in the respec- 
tive columns. Their temperature may be made such as to cause a 
variation in their heights, of a foot in every twenty-three feet, or over 
four feet per hundred. 

Water often descends into the ground warmer and less dense than 
it returns. By* descending a few feet into the earth, we find our- 
selves below the influence of the impinging of the sunbeams on the 
surface, and arrive at a stratum of invariable temperature, which 
absorbs this extra heat. As the water becomes more dense, it con- 
tinues to descend, and takes the place of that below, which has been 
made less dense by the internal heat, and is in its turn expanded, 
and again returned to the surface in the form of a spring. If its 
transit to the surface is very direct and quick, it may return hot. If 
the temperature of the descending column is reduced to that of the 
stratum of invariable temperature, through which it passes, the tem- 
perature of the ascending column may be reduced nearly as low, and 
the water be returned to the surface, cooler and more dense than 
when it left. Thus while the water of a refreshing shower may 
enter the ground warm and insipid, it may be returned to the sur- 
face a cool and invigorating spring. The undulating surface and 
impervious structure of some of the inferior strata are such, that 
natural drainage, (which is usually assigned as the cause of springs, 
whether from natural or artificial apertures,) is an important agent 
in their production. These two forces may act separately or unitedly, 
in the production of springs. 



21 

As water free to move, does not sensibly conduct heat, and is but 
slightly compressible, it may be found with its density increased by 
pressure, and still indicate a very high or a very low temperature, if 
the pressure is such that it cannot expand to steam or ice. 

As cold water is heavier than warm, and salt water heavier than 
fresh, when the distribution of water at the equator is equal to the 
evaporation, the colder and heavier waters of the polar regions may 
move towards the equator in an undercurrent, and when the evapo- 
ration is nearly constant, or greater than the distribution, the hotter, 
Salter, and heavier waters may sink to an equal depth and move in 
an opposite direction. 



tfttJ 



&mu www* % 



THE SOLAR SYSTEM. 



Having noticed a few of the effects of gravitation on the earth, I 
shall very briefly consider its condensing effects on the Solar System ; 
as matter throughout the universe is equally attracted by gravitation, 
and obeys the same mechanical laws. 

The effect of gravitation on the density and peculiar motion of the 
moon. As the force of gravitation decreases as the distance increases, 
and the density of matter depends on the force of gravitation, the 
inferior limb of the moon must be denser than the superior limb. 

The distance between the sun and moon being far greater than 
the distance between the earth and moon, the unequal attraction of 
the earth on the opposite limbs of the moon, greatly exceeds that of 
the sun on its opposite limbs. The preponderance of gravity on the 
denser portion causes the moon to be a balanced figure, exposing only 
its loaded or denser limb to the earth. This explains the singular 
phenomenon of the apparent uniform rotation of the satellites on 
their axes, with each revolution in their orbits, (as is supposed to be 
the case with the satellites of Jupiter,) although the length of their 
orbits and times of revolution are unequal. The balanced position 
of the moon is the more stable, when its denser portion is turned 
towards the earth and sun, as when the moon is in opposition to the 
sun. But the unequal orbital motion of the moon, and varying, 
angular position of the sun, with its unequal gravitating influence on 
the opposite limbs of the moon, pauses the oscillations called the 
librations of the moon, in latitude as well as in longitude, as the 
moon is balanced towards the center of the earth, and its path varies 



24 

from the ecliptic. On account of the balanced condition of the moon 
and inclination of its orbit, its polar axis is inclined to the ecliptic. 

The conditions of the crust, and the unequal amount of land and 
altitudes in the two hemispheres, depend on gravitation. The thick- 
ness, density, conducting power and temperature, of the crust of the 
earth, at the surface, depend on the force of gravitation. On ac- 
count of the feeble force of lunar gravity on the surface of the 
moon, owing to its diminutive size, when compared with the earth, 
its crust must be very thick and rare, and its density and surface 
temperature much less than that of the earth : for the same reason, 
its atmosphere must be very rare. As the unequal refrigeration and 
contraction of the interior and exterior portion of the crust, caused 
the inequalities on the surface of the earth, and as rarer matter con- 
tracts more in congealing, the contraction and formation of a rare 
and thick crust must cause great surface inequalities, as the disk of 
the moon indicates. The crust of the earth is the lightest, as well as 
rarest, and thickest, at the equator. The greatest surface inequalities 
are therefore found in the warmer climates, as is seen in the altitude 
of table lands and mountain ranges. The crust being the rarest, 
lightest, and most elevated, where it is the least affected by gravita- 
tion, more than one-half of the land and the greater altitudes, are 
located in the northern hemisphere. For with the inclination of the 
earth on its axis and motion in its orbit, the south pole approaches 
nearer to the sun, than the north pole, subjecting it to more powerful 
attraction. The unequal influence of the sun on the opposite limbs 
of the earth, increases as the distance between them decreases. The 
variation in the force of gravitation in the two hemispheres, is exceed- 
ingly slight, and the variation in the altitudes is also very trifling, 
when compared with the mass of the earth. 

The density and physical condition of the planets are determined 
by the force of gravitation. The decrease in the density of the 
planets, as the force of gravitation on them decreases, indicates a 
similarity of substance. If exactly similar, the ratio between their 
density and distance from the sun would not be regular, as the force 
of gravitation varies with their mass, figure, surface temperature, and 
the gravitating influence of each on the other, (as the effect of the 
moon on the earth,) as well as with their distance from the sun. 

The density and conducting power of the crust of the earth would 
be increased, and its thickness would be reduced, if the force of 



25 

gravity should be increased. The crust of the larger planets must, 
therefore, be very thin and dense, causing a high surface temperature, 
which would rapidly convert the surface fluids into a vapory envelope, 
greatly reducing the density of those planets when taken as a whole. 
The loss of gravity must cause the surface of the exterior envelope 
of vapor, to be very rare, with a correspondingly low temperature, 
as is the case with our upper atmosphere. The reflective power of 
vapor is greatly increased in this condition, and far exceeds that of 
land and water. That their outer envelopes are in this condition, is 
indicated by their great reflective powers, as well as by their variable 
surfaces. 

The rapid motion of these planets on their axes, causes their 

equatorial diameters largely to exceed their polar diameters. When 

> fluids are very sensibly elevated by centrifugal force, it is a law in 

mechanics that they will form more or less in ridges at right angles 

with the axis of rotation. 

Light reflected from deep ravines and elevated ridges, would cause 
the surface to appear variegated, and ridges formed of vapor must 
undergo frequent changes by condensation. The physical disturbing 
forces, on these planets, must have great energy, caused in part by 
the rapid evaporation and condensation, which would give unceasing 
activity to the leveling forces ; and also by their rapid rotation on 
their axes, and the mass, and unequal revolutions of their moons. 
These, together with the near approach of the fluid line to their sur- 
faces, would cause volcanic action on a very grand and extensive 
scale. »The immense volumes of dark and heated vapor that ascend 
at times, would reduce the reflective power of the overhanging vapor 
on a very large extent of surface. At other times, eruptions would 
cause a vast extent of surface to be covered with molten matter. 
The heat ascending from such extensive fields of melted lava would 
disperse, in a measure, and illuminate the vapor hanging over an 
immense extent of surface. These convulsions may cause the more 
permanent spots on the disk of Jupiter ; those which do not always 
disappear with a reconstruction of the belts. 

As unlike density and temperature admit of different chemical 
combinations, the unlike density and temperature of the planets may 
cause their various colors. 

The expansive force of heat is the most apparent where matter is 
the least encumbered with gravitation. * A high surface temperature 
4 



26 

would, therefore, greatly inflate the outer envelope, as the larger 
masses indicate. The same expansive force may be perceptible on 
some of the comets, as they approach the sun. 

Heat the equivalent of gravitation. Light the effect of heat. The 
immense power of gravitation in the sun, causes the line of uniform 
density to be located so near the surface, that the refrigerating forces 
are insufficient for congelation, except now and then the formation of 
comparatively small spots or thin, floating islands, on some portion 
the least affected by gravitation, as some point on the equator ; and 
they are soon liquified by a relative change of position. The expan- 
sive force caused by their rapid liquifaction, may account for the lofty 
protuberances which have been seen projecting from the surface of 
the sun. The expansive force of heat and powerful condensing effect 
of gravitation on the surface of the sun, must cause the exterior en- 
velope to be very dense, highly heated gas ; as it were a very dense 
blaze, reflecting light accordingly. 

The naturally depressed condition of the floating islands, accounts 
for the apparent openings, where there is a visible island. That the 
gas overhanging the edge or shore of these islands, is to some extent 
illuminated by the melted nucleus, producing the penumbra, is indi- 
cated by its disappearing, when any two or more contiguous islands 
intercept the light. 

The faculse may be caused by the accumulation of the floating 
specks in clusters, owing to their mutual attraction, thereby increas- 
ing the brightness of the surrounding surface, just before the visible 
formation of an island. When the island first disappears, its perfect 
fluidity may also cause increased brightness. 

That the sun must reflect light, is made apparent by the fact that 
matter sufficiently condensed is hot and luminous, and as the tem- 
perature of a stratum depends on its density, the light of the sun 
must be as permanent as gravitation. 

"spare moments." 
April, 1863. 



LIBRARY OF CONGRESS 



003 536 992 2 



